There is no question that DNA evidence has helped a great many innocent people achieve exoneration of criminal charges, some of whom have spent decades languishing in prison. A fair number of people have also been arrested and convicted based on the compelling nature of DNA evidence, which brings us to the recent announcement of an arrest in Phoenix that – through alleged DNA matching – has linked a man picked up in Arizona to two Virginia armed robberies.
Police on Tuesday identified the man as McKinley Brown, 24, and said he was being held in Arizona on suspicion of aggravated assault, sexual assault, and kidnapping. The charges against Mr. Brown, both those alleged in Virginia and Phoenix, are obvious quite serious. It is important to remember, however, that presence of one’s DNA at a crime scene does not guarantee that they committed a crime.
DNA testing and DNA evidence is highly regarded and therefore frequently relied upon in many criminal cases. That does not mean that this form of evidence is foolproof. There are a number of issues that can arise with regard to DNA evidence, resulting in inaccurate or inconclusive results. One of the biggest problems with the handling of such evidence can occur through a process known as cross-contamination. Cross-contamination can occur when law enforcement authorities or lab technicians are sloppy in their work. In most cases, cross-contamination occurs when the DNA that is being tested is accidently mixed with the DNA of the forensic scientist or it is mixed with samples provided to the lab for comparison. The recent admission by the Justice Department that its task force failed in its duties to properly review the FBI crime lab amid scathing reports of potential errors in possibly hundreds of cases dating back several years is chilling proof of that fact.
Given the deeply disturbing nature of the FBI scandal, and the gross mismanagement and oversight by the Justice Department, a number of political leaders and justice advocates – such as the Innocence Project — are pushing for the adoption of better scientific standards in forensic testing and a more open process for the disclosure of evidence in criminal proceedings. This could include expanding the role of the National Institute of Standards and Technology and the National Science Foundation. The National Academy of Sciences recommended back in 2009 that a national forensic science entity needed to be created and yet here it is 2014 and we are still waiting.
Given these issues, we are deeply concerned that reports of Mr. Brown’s arrest and his alleged DNA match will unduly influence members of the pubic who could be called upon to serve as jurors should his case proceed to trial. Armed robbery in the Commonwealth of Virginia is a felony offense and includes the threat of severe penalties, such as lengthy prison time and costly fines. Such serious charges and potentially serious penalties require responsible presentation facts and handling of the evidence.